If you want to get the WotLK expansion on release day, it looks like there are two options:

Wait in line for hours the night before. Of course, this only works if you live in New York, Austin, Anaheim, or San Francisco.[1]

Just pre-order it from Amazon and choose "Release-Date Delivery" when you're checking out. This means they'll ship the game to you in advance so that it actually shows up on your door on release day. Perhaps shipping will even be fast and you'll get it a bit early. ;) You can also order the official WotLK strategy guide.

P.S. We're working on the Northrend maps and should have them up soon!